RU2678548C1 - Blockage in the lance removing method and device - Google Patents

Abstract

FIELD: metallurgy.SUBSTANCE: invention relates to the field of metallurgy and can be used for the blockage removal in the direct-melting converter solid particles injection lance. Direct-melting converter comprises the molten metal and slag bath and passing into the direct-melting converter solid particles injection lance, which has immersed into the molten slag outlet end. Solid particles injection lance additionally has a single inlet connected to the section of gas and solid remelting material supply line into the solid particles injection lance. Method comprises the obstructions removing tool advancing through the supply line section and through the solid particles injection lance to the upstream obstruction side, the tool operating under the elevated gas pressure conditions for the obstruction removal so, that the remelted solid material and the gas were supplied through the solid particles injection lance, and the tool removal from the solid particles injection lance and the supply line section. Also disclosed is the obstruction in the solid particles injection lance removal device.EFFECT: invention allows to remove blockages in the solid particles injection lance during the direct melting converter operation without its stopping.19 cl, 7 dwg

Description

FIELD OF THE INVENTION

The present invention relates to the removal of blockages in the lance for injection of solid particles. More specifically, the present invention relates to a method and apparatus for removing blockages in a tuyere for injecting solid particles.

The present invention relates specifically, although not exclusively, to tuyeres for injecting solid particles from a direct melting converter, such as a direct melting converter based on the use of a melting bath, for producing molten metal such as iron in a direct melting process.

The present invention has applications in metallurgical melting processes based on the use of a melting bath, which include injecting solid materials under pressure into the melting bath through an outlet located inside the melting bath. The present invention also has applications in manufacturing and processes that include the transfer of solid remelted materials through transfer.

BACKGROUND

The well-known melting process based on the use of a melting bath is generally called the “HIsmelt” process and it is described in a significant number of patents and patent applications filed in the name of the present applicant.

The HIsmelt process is generally applicable to the melting of metal-bearing material, but is especially associated with the production of molten iron from iron ore or other iron-containing material.

In the context of producing molten iron, the HIsmelt process includes the steps of:

(a) forming a bath of molten iron and slag in the main chamber of the direct melting converter;

(b) injection into a smelting bath: (i) iron ore, usually in the form of fines; and (ii) a solid carbonaceous material, usually coal, which serves as a reducing agent for the remelted iron ore material and as an energy source; and

(c) melting iron from iron ore in a bath.

The term "melting" in this document should be understood as heat treatment, while chemical reactions that reduce the content of metal oxides occur with the formation of molten metal.

Another known process for melting metal-bearing material is hereinafter referred to as the “HIsarna" process. This process is carried out in a melting device containing (a) a melting converter, which contains tuyeres for injecting solid particles and tuyeres for injecting oxygen-containing gas and is configured to contain a bath of molten metal, and (b) a melting cyclone for pretreatment of metal-bearing melted material which is located above the smelter and communicates with it. The HIsarna process and device are described in international application PCT / AU 99/00884 (WO 00/022176) filed in the name of the present applicant.

In the HIsmelt process, solid remelted materials in the form of a metal-bearing material (which can be preheated) and a carbon-containing material and, optionally, a flux are injected into the melting bath through several water-cooled tuyeres to inject solid particles that are inclined with respect to the vertical so that pass down and in through the side wall of the main chamber of the melting converter and into the lower region of the converter so as to deliver at least a portion of the solid remelted m materials under the metal layer in the bottom of the main chamber. Solid remelted materials and carrier gas penetrate the melting bath, as a result of which molten metal and / or slag extends into the region above the surface of the bath and forms a transition zone. A stream of oxygen-containing gas, usually enriched with air oxygen or pure oxygen, is injected into the upper region of the main chamber of the converter through a downward lance to cause subsequent combustion of gas reaction products discharged from the melting bath in the upper region of the converter. In the transition zone there is a suitable mass of rising and then dropping drops, or splashes, or streams of molten metal and / or slag, which provide an effective medium for transferring thermal energy to the bath resulting from the subsequent combustion of gas reaction products over the bath.

Usually, in the case of the production of molten iron, when using oxygen-enriched air, oxygen-enriched air is generated in air heaters and is supplied at a temperature of about 1200 ° C. to the upper region of the converter main chamber. When using technical cold oxygen, technical cold oxygen is usually supplied to the upper region of the main chamber at ambient temperature or at a temperature close to it.

The flue gases resulting from the subsequent afterburning of the reaction gas products in the smelter are discharged from the upper region of the smelter through the flue gas duct.

The melting converter comprises a main chamber for melting the metal-bearing material and a front hearth connected to the main chamber by connecting the front hearth, so that a continuous outflow of metal production from the converter is possible. The main chamber includes sections with a refractory lining in the lower part of the hearth and water-cooled panels in the side walls and the arch of the main chamber. Water is continuously circulating through the panels in a continuous circuit. The front furnace performs the function of a siphon gate filled with molten metal, which naturally “spills” excess molten metal from the smelter during its production. This allows you to obtain information about the level of molten metal in the main chamber of the melting converter and adjust it with small tolerances - which is extremely important for production safety.

In the HIsarna process, carbonaceous remelted material (usually coal) and flux (usually quicklime) are injected into the melting bath in the melting converter through tuyeres for injecting solid particles.

Solid remelted materials in both the HIsmelt and HIsarna processes are usually presented in the form of fines, and in some cases clogging of solid remelted materials in the inner tube of the tuyere for injecting solid particles can occur.

One solution to this problem is to remove the clogged inner pipe from the lance and replace it with another inner pipe. Another option is to drill a plug in atmospheric conditions. This last option requires stopping the production and partial drilling of the slag layer of the melting bath. Additionally, the pressure in the plugged lance must be reduced before drilling or replacing. Then, the melting process should be restarted by eliminating the drilled slag and increasing the supply of solid remelted material over a period of time.

The present invention provides a method for removing blockage in a lance for injecting solid particles without completely stopping production and eliminating slag.

The above description should not be construed as recognition of well-known knowledge in Australia or elsewhere.

SUMMARY OF THE INVENTION

The present invention is a method for removing blockage in a tuyere for injecting solid particles under normal conditions of operation of the direct melting converter, which contains a bath of molten metal and slag, the tuyere for injecting solid particles passes into the direct melting converter and has an outlet end that is immersed in the molten slag , and has a single inlet connected to a section of the supply line that delivers gas and solid remelted material to the lance for injecting solid particles, when the section of the feed line is located upstream and is coaxial with the tuyere for injecting solid particles, the method includes:

(a) advancing the obstruction tool through the feed line section and through the solids injection tuyere to the upstream side of the obstruction;

(b) operating the tool under conditions of increased gas pressure to remove clogging so that solid remelted material and gas can flow through the tuyere to inject solid particles and into the direct melting converter, while the gas pressure is increased so as to avoid slag entering the outlet lance end; and

(c) removing the tool from the lance for injecting solid particles and sections of the feed line.

Removing the blockage thus eliminates the need to remove and replace the inner tube from the lance for injecting solid particles during plugging. This means that a shutdown of production is optional. This also means that the partial elimination of the slag stock is not necessary, since the molten slag in the bath is below the outlet end of the lance. Returning to normal production volumes after these steps involves restoring slag stock, since slag stock is important for the HIsmelt process, and includes increasing the flow of metal-bearing material over time to ensure that the temperature of the melting bath is maintained at the optimum melting temperature. The combined influence of both factors prolongs the time to return to normal production volumes. The method described above thus allows production to continue, albeit in smaller volumes, and reduces the time to return to normal production volumes.

Under normal operating conditions, solid particles transported in the carrier gas at a pressure higher than the gas pressure in the direct melting converter are supplied to the tuyere for injecting solid particles, and the method may include maintaining the carrier gas so that the section of the feed line and the tuyere are arranged upstream of the blockage, remained at a pressure higher than the gas pressure in the direct melting converter.

The method may include shutting off the carrier gas and may include providing increased gas pressure by supplying pressurized purge gas to a solids injection tuyere upstream of the plug so that the purge gas flows into the direct converter by removing the plug. melting.

The method may further include resuming the carrier gas supply after removing the blockage and reducing and ultimately stopping the purge gas supply after the carrier gas supply has begun.

The method may further include reducing the pressure in the tuyere for injecting solid particles and upstream sections of the supply line located upstream of the blockage, advancing the tool to remove the blockages to the blockage, and again increasing the pressure in the tuyere for injecting solid particles and the section of the supply line before the use of a blockage removal tool to remove blockage.

Re-increasing the pressure in the lance for injecting solid particles and the supply line section may include supplying purge gas to the section of the supply line and to the lance for injecting solid particles, located upstream relative to the blockage. Alternatively, re-increasing the pressure in the tuyere for injecting solid particles and the supply line section may include restarting the carrier gas supply.

The pressure in the direct melting converter can be from 0.5 bar gauge to 1.2 bar gauge under normal operating conditions.

The method may further include, after step (a) and before step (b), removing solid material from the tuyere to inject solid particles and sections by blowing.

The tool may be a drilling device, and the method may include removing the blockage by drilling the blockage.

Removing the blockage may include drilling a blockage near the inner side wall of the lance for injecting solid particles to loosen the blockage at the junction with the side wall.

Step (b) may include connecting the tool to a series of extension rods and advancing the rods into the feed line section and the lance for injecting solid particles until the tool reaches a blockage.

The transportable solid material may contain metalliferous material.

The transportable solid material may contain metalliferous material and carbon-containing material.

The transportable solid material may contain metalliferous material, carbonaceous material and flux.

The metal-bearing material may be iron ore. Iron ore may be preheated to a temperature of at least 500 ° C. Iron ore can be presented in the form of trifles.

The transportable solid material may contain carbonaceous material.

The carbonaceous material may be coal.

The present invention extends to situations in which only metal-bearing material is injected into the direct melting converter via a tuyere.

The present invention extends to situations in which only carbon-containing material is injected into the direct melting converter via a tuyere.

The present invention also provides an apparatus for removing blockage in an injection lance for injecting solid particles into a direct melting converter, wherein the injection lance for injecting solid particles has a single inlet connected to a supply line section that supplies gas and solid particles to the injection lance for solid particles and which is located upstream and is coaxial with the tuyere for injecting solid particles, while the device contains a tool that passes through a section of the feed line and a lance for injecting solid particles to remove clogging of solid material; and an assembly unit for moving the tool through a lance for injecting solid particles and a section of the feed line to the clogging with the upstream side of the clogging.

The device may further comprise a gas pressure shutter that maintains the gas pressure in the lance for injecting solid particles and the feed line section above the gas pressure in the direct melting converter during normal operation, while the tool advances to the plug, works to remove the plug and is removed from the line section supply and tuyeres for injection of solid particles.

The tool may comprise a drill head and a drill device operably connected to the drill head to cause rotation of the drill head.

The advance assembly unit may comprise several drill extensions that can be connected in series to increase the length of the working connection between the drilling device and the drill head.

The advancement means may further comprise a drive device for advancing the drill head and drill extension extensions along the lance for injecting solid particles and extracting the drill head and drill extensions from the drill lance for injecting solid particles.

The drive device may be a platform mounted on a rail, to which a drilling device for reciprocating motion, coaxial with the tuyere for injecting solid particles, is attached, and drill extensions include interconnecting links so that the reciprocating movement of the platform mounted on the rail guide causes a corresponding movement of extension cords for drill and drilling device.

The device may further comprise an isolation valve located upstream of the tuyere, to ensure the introduction of the tool into the tuyere for injection of solid particles and its extraction from it under atmospheric pressure.

BRIEF DESCRIPTION OF GRAPHIC MATERIALS

The present invention is further described solely by way of example with reference to the accompanying drawings, in which:

in FIG. 1 shows a vertical cross-sectional view of a direct melting converter, which is part of an embodiment of a direct melting apparatus according to the present invention;

in FIG. 2 is a schematic view that illustrates an injection system of a metal-bearing material and a carbon-containing material that delivers a transportable solid material to a tuyere for injecting solid particles of a direct melting converter;

in FIG. 3 is a schematic view of a solid particle injection lance and a feed line with an embodiment of the aforementioned blocking device; and

in FIG. 4 is a side plan view of a blocking device shown in FIG. 3, with a partial cross-sectional view of a drill body illustrating a drill head inside a drill body;

in FIG. 5 is a cross-sectional view of the spherical valve and drill body shown in FIG. 4, along the longitudinal axis of the drill body; and

in FIG. 6A and FIG. 6B shows side views of the drill head and extension rod shown in FIG. four.

DESCRIPTION OF EMBODIMENTS

In FIG. 1 shows a direct melting converter 11, particularly suitable for carrying out the HIsmelt process, as described by way of example in international patent application PCT / AU 96/00197 (WO 1996/031627) filed in the name of the present applicant.

The following description is made in the context of melting iron ore fines for the production of molten iron according to the HIsmelt process.

It should be understood that the present invention is applicable to the melting of any metal-bearing material, including ores, partially reduced ores and metal-containing waste streams, by any suitable direct melting process based on the use of a melting bath, and is not limited to the HIsmelt process. It should also be understood that ores can be represented as iron ore fines.

The converter 11 comprises a hearth, which includes a base 12 and sidewalls 13 made of refractory bricks, side walls 14 that form a generally cylindrical barrel extending upward from the sidewalls 13 of the hearth, and a vault 17. Water-cooled panels (not shown) are provided for transmission heat from the side walls 14 and the roof 17. The converter 11 is further equipped with a front mining 19, by means of which the molten metal is continuously discharged during melting, and a drain hole 21, by which the molten slag is periodically unloaded tsya during melting. The vault 17 is equipped with an outlet 18 through which exhaust gases generated during the process are discharged.

When using converter 11 for melting iron ore fines to produce molten iron according to the HIsmelt process, converter 11 comprises a melting bath of iron and slag, which comprises a molten metal layer 22 and a molten slag layer 23 on the metal layer 22. The position of the nominal unperturbed surface of the metal layer 22 is shown by arrow 24. The position of the nominal unperturbed surface of the slag layer 23 is shown by arrow 25. The term "unperturbed surface" means the surface in the absence of injection of gas and solid particles into the converter 11. Under normal operating conditions, the process occurs in the pressure range from 0.5 bar gauge to 1.2 bar gauge and preferably from 0.6 bar gauge to 1.0 bar gauge.

The converter 11 is equipped with tuyeres 27 for injecting solid particles passing down and in through holes (not shown) in the side walls 14 of the converter and into the slag layer 23. Particulate tuyeres 27 are described in more detail in connection with FIG. 3 and FIG. 4. Two tufts 27 for injecting solid particles are shown in FIG. 1. However, it should be understood that converter 11 may have any suitable amount of such tuyeres 27. In operation, heated iron ore fines and coal having an ambient temperature (and fluxes, usually lime) are transferred in a suitable carrier gas (such as a carrier gas with a small amount of free oxygen, usually nitrogen) and are separately supplied to the tuyeres 27 and are jointly injected through the outlet ends 28 of the tuyeres 27 into a melting bath and preferably into a metal layer 22. The following description is made in the context of the use of nitrogen as a carrier gas for iron ore fines and coal.

The outlet ends 28 of the tuyeres 27 for injecting solid particles are placed above the surface of the metal layer 22 during the process and immersed in the slag layer 23. This arrangement of tuyeres 27 reduces the risk of damage caused by contact with molten metal, and also allows tuyeres to be cooled by forced internal water cooling, as further described below, without a significant risk of contact of water with molten metal in converter 11.

The converter 11 also contains a lance 26 for injecting gas, designed to deliver a stream of hot air to the upper region of the converter 11. The lance 26 passes down through the arch 17 of the converter 11 to the upper region of the converter 11. During operation, the lance 26 receives a stream of oxygen-enriched hot air through the delivery pipe hot gas (not shown) that passes from the hot gas supply station (also not shown).

In FIG. 2 schematically shows one embodiment of a direct melting apparatus according to the present invention to the extent that the apparatus is associated with supplying heated iron ore fines and coal having an ambient temperature to one lance 27 for injecting solid particles.

The apparatus comprises a direct melting converter 11 shown in FIG. one.

The apparatus also comprises a pre-treatment unit 34 in the form of a pre-heating device for heating iron ore fines, usually to a temperature of at least 600 ° C. The preheater may be any suitable type of preheater.

The installation also contains an ore delivery system for supplying iron ore fines to tuyeres 27.

The ore delivery system comprises (a) an ore accumulation / distribution unit 32 for accumulating and distributing heated iron ore fines and (b) an ore supply line 36 for supplying heated ore from the ore accumulation / distribution unit 32 to the tuyeres 27.

The ore storage / distribution unit 32 is designed to accumulate and distribute heated iron ore fines carried in a nitrogen carrier gas. The ore storage / distribution unit 32 can be represented as a plurality of compartments, which allows the transfer of heated iron ore fines from standard atmospheric conditions to pressurized carrier gas conditions. However, for the purposes of the present invention, the ore storage / distribution unit 32 may be considered as a single unit. The pressure of the carrier gas is increased so that the pressure drop from the inlet end 29 of the tuyere 27 for injecting solid particles to the outlet end 28 is at least 1 bar.

In operation, iron ore fines are fed to a preheater 34 from a warehouse (not shown) and the preheater heats the fines. The pre-heating device 34 is configured to heat the fines so that the fines have a temperature of at least 500 ° C and usually in the order of 600 ° C to 700 ° C at the injection point into the converter 11. Exhaust gases can be supplied from the outlet 18 to the device 34 preheating so that heat can be transferred from the exhaust gases to the iron ore fines. The pre-heating device 34 is configured to supply heated iron ore fines to the ore storage / distribution unit 32.

The ore supply line 36 for transporting heated iron ore fines from the accumulation / distribution unit 32 to the tuyere 27 contains (a) a first section 48, which transfers the fines directly to the converter 11, (b) an upward section 42, which delivers the fines from a position of approximately at the level of the base 12 of the converter 11, to a position at least at the height of the lance 27, and (c) a downward section 46 that connects the line with the ore inlet to the lance 27. Section 46 is designed in such a way that it is aligned with the lance 27 in operating position as shown in FIG. . 2, and defines a single channel that delivers gas and solid particles to the inlet end 29 of the lance 27 for injecting solid particles. In other words, section 46 does not contain branching compounds that are connected to additional sources of gas or particulate matter.

The installation also contains a separate coal delivery system for supplying coal to the lance 27.

The coal delivery system is presented in the same form as the ore delivery system described above, except that the coal is not preheated before being fed into the lance 27. Additionally, the coal delivery system typically delivers coal and flux, for example, lime.

Coal is delivered from the warehouse to the coal storage / distribution unit 38, which accumulates coal at ambient temperature. The flux 50 is supplied separately to the coal storage / distribution unit 38. A feed line 40 connects the coal storage / distribution unit 38 to the ore feed line 36. If the ore has been preheated, the supply line 40 delivers coal and flux to section 46. However, in any case, the lance 27 for injecting solid particles has a single inlet connected to section 46, which itself has a single channel for solid particles and gas. This means that there is essentially a single supply of solid particles and gas to the tuyere 27 for injecting solid particles. However, for simplicity, the feed line is shown in FIG. 2 as delivering coal and flux to the first section 48 of the ore supply line 36.

In operation, the coal and flux at ambient temperature are discharged from the coal storage / distribution unit 38, transferred to a nitrogen carrier gas, and transported through the coal supply line 40 to the first section 48 of the ore supply line 36 so that the ore and coal are transferred together to the lance 27.

The coal accumulation / distribution unit 38 can be represented as a plurality of compartments, which makes it possible to transfer coal from standard atmospheric conditions to conditions of a nitrogen carrier gas under pressure. However, for the purposes of the present invention, the coal storage / distribution assembly unit 38 may be considered as a single unit.

The lance junction with the ore supply line 36 is shown in FIG. 3 with a device for removing blockages in the form of an assembly unit 60 for drilling a lance. Sections 42 and 46 of the ore supply line 36 have the same inner diameter for supplying the transported solid materials to the tuyere 27 for injecting solid particles. The upper end of section 46 extends up and out beyond the line of section 42 into the tuyere purge system 54, which is configured to remove solid particles and gas from sections 42 and 46. The tuyere purge system 54 contains a discharge line 56 extending from the very beginning perpendicular from the top the end of section 46, and further comprises a vent valve 58 that controls the flow of gas and particulate matter through the discharge line 56. The highest end of section 46 ends with a flange 59 (in FIG. 4), to which an assembly unit 60 can be connected Furling lances.

The lance drilling assembly 60 includes a spherical valve 62 with flanges 64 located at each end. One flange 64 is connected to a flange 59 of the first section 46, and another flange 64 is connected to an end flange 78 of the drill body 76. The drill 90 (Fig. 5 and Fig. 6A) is contained in the housing 76 for the drill. The body 94 of the drill 90 is contained in the sleeve section 79 of the housing 76 for the drill. The stuffing box 84 has a series of handles and an external thread that interacts with the internal thread of the sleeve section 79. The rotation of the stuffing box 84 relative to the sleeve section 79 advances the stuffing box 84 into the sleeve 79 and seals the graphite packing 80, thereby forming a gas tight seal around and around the sleeve wall 79 the outer wall of the body 94 of the drill 90. The lock 82 is equipped with an internal thread that interacts with the external thread of the stuffing box 84. When the gas tight seal is formed by the stuffing box 84, pressing graphite on bead 80, the lock 82 is advanced along the thread on the gland 84 until it is firmly pressed against the sleeve section 79. This prevents the gland 82 from loosening in the drilling position. When the lance drilling assembly 60 is not operational, the spherical valve 62 is closed to isolate the lance drilling assembly 60 from the ore supply line 36. Additionally, the drill 90 is fixed in the housing 76 with a latch 88 passing through the gland 84 and the fixing hole 100 in the drill 90.

An assembly assembly 66 of a support structure extends from the drill body 76, which includes a zigzag bracket 68, a rail for supporting the drill 70 parallel to the housing 76 for the drill, and a connecting beam 72 extending between the bracket 68 and the rail 70 for supporting the drill. A platform 74 is mounted on the rail 70 to support the drill for free movement along the rail 70. The drilling device 77 is mounted on the platform 74 and has a drill head 75 that has a rotation axis coaxial with section 46 and tuyere 27 for injecting solid particles.

The drill 90 comprises a hollow cylindrical head 92 extending forward from the body 94 and has teeth extending from the head 92 to cut a blockage in the tuyere 27 for injecting solid particles. The hollow cylindrical head 92 provides for drilling a plug near the inner wall of the feed pipe in lance 27 for injecting solid particles. Drilling at this point displaces the fines from the blockage and leads to weakening of the blockage at the junction with the inner side wall of the tuyere 27 for injecting solid particles. Accordingly, it is assumed that the blockage will fall away from the side wall, and fines will flow into the direct melting converter 11 with purge gas.

The body 94 includes a connecting recess 96 at the end of the drill, opposite the head 92. The connecting recess 96 has a profile corresponding to the profile of the connecting protrusion 104 of the extension rod 102 (Fig. 6B). Both the drill 90 and the extension rod 102 comprise a connecting hole 98 adjacent to the corresponding connecting recess 96 and the connecting protrusion 104. A connecting pin (not shown) is used to connect the adjacent extension rods 102 and to connect the extension rod 102 and the body 94. In particular , the connection passes through the connecting hole 98 on each of the adjacent extension rod 102 or body 94.

The locking holes 100 hold the latch 88 in such a way that the extension rods 102 and the drill 90 can be locked relative to the housing 76 while additional extension rods 102 are added or removed as the drill 90 moves or is removed. In particular, when the drill 90 is removed, the gas pressure in the section 46 will push the drill 90 and extension rods 102 out of section 46. Accordingly, each extension rod 102 is locked by a latch 88 with a gland 84 while the drilling device 77 is connected to the extension the second rod 102. When the connection is made, the latch 88 is removed, and the drilling device 77 and the platform 74 control the extraction of the extension rod 102. The next sequential extension rod 102 passing through the housing 76 will then be locked by the latch 88 relative to the gland 84, while the drilling device 77 continues removed and the outer extension rod 102 is separated from the locked extension rod 102. The process is repeated until all extension bars are removed and the drill 90 will not be fixed in housing 76.

If clogging occurs in the lance 27 for injecting solid particles, the only access to the clogging exists only through a single inlet 29 in the lance 27 for injecting solid particles. Given that it is important to timely remove the blockage, removing upstream sections of the supply line 48, such as section 46 and section 42, to access the inlet end of the lance 29 before removing the blockage and replacing the upstream sections after removing the blockage will result in significant loss of time. For this reason, the blockage is removed without removing sections 42, 46 of the supply line. As a result, controlling the gas pressure upstream of the plug includes controlling the gas pressure in the section 46 upstream of the inlet end 29. Further, access to the plug for the lance drilling assembly 60 is limited by access through the section 46 and the lance inlet 29.

When clogging occurs in lance injection tuyere 27, the supply of solid materials from sections 42 and 46 is interrupted due to clogging. To be more precise, clogging impedes the flow of carrier gas, which means stopping the transfer of particulate matter. However, the supply line 48, 42, 46 and the lance 27 for injecting solid particles, located upstream relative to the blockage, remain under pressure, while the pressure exceeds the gas pressure in the direct melting converter under normal operating conditions.

In one embodiment, the tuyere drilling assembly unit 60 advances to obstruction through section 46 and the tuyere injection section 27 of solid particles located upstream of the obstruction. The assembly unit 60 then works to remove the obstruction, and as soon as the obstruction is removed (when the carrier gas flows through the supply line 48, 42, 46 and into the converter with solid materials transported in the flowing gas), the assembly unit is freely removed from section 46.

More specifically, the lance drilling assembly 60 then gains access to the lance 27 for injecting solid particles by opening the spherical valve 62. The drill 90 is advanced along section 46 by connecting the extension rod 102 to the rear end of the drill 90 by installing the connecting protrusion 104 in the connecting recess 96 on the drill 90. The latch 88 is removed from the drill 90 and placed in the connecting hole 98 in the extension rod 102. Then the extension rod 102 is advanced into the housing 76 for the drill to the point and where the latch 88 fits into the gland 84. The process of connecting the additional extension rods 102 and moving them into the drill body 76 leads the previous extension rods 102 and drill 90 to advance along section 46 until the drill 90 reaches a blockage in the lance 27 for injection of solid particles. At this point, the gland 84 rotates so that it moves along the sleeve section 79 to seal the graphite packing 80 and to form a gas tight seal in the drill housing 76 around the extension rod 102. Then, the lock 82 is advanced so as to lock the gland 84 in this position . Then, the drilling device 77 is advanced along the rail guide 70 to support the drill so that the drilling head 75 enters the connecting recess 96 on the extension rod 102, which extends outward from the housing 76 for the drill.

Then, the drilling device 77 is operated so that the drill drills a blockage. Once the plug is removed and the carrier gas flows through section 46 and the lance 27 for injecting solid particles, the drilling device 77 is removed along the rail 70 to support the drill so that the extension rods 102 can be removed from section 46 and subsequently removed while the drill 90 will not be contained in the drill body 76. The latch 88 is placed in the fixing hole 100 in the drill 90 to fix the drill 90 in the housing 76 for the drill. The spherical valve 62 is then closed to isolate the lance drilling assembly 60 from section 46. At this point, the gas pressure in the housing 76 is still an increased purge gas pressure. Accordingly, the tubular section 79 includes an air exhaust valve 81 for controlled discharge of gas under pressure from the housing 76.

In an alternative embodiment, the blockage is removed, first of all, by closing the valve 52 (shown schematically in FIG. 3). Due to the fact that section 46 is still under pressure, solid particles are blown out of section 46 by opening the vent valve 58 to allow solid particles and gas under pressure to pass through a discharge line 56 in the tuyere purge system 54. Opening the vent valve 58 reduces the pressure in the section 46, located upstream relative to the blockage, and the section of the section 42, located downstream relative to the valve 52. In this embodiment, the pressure in the section 46 and the section section 42 is reduced to ambient pressure.

The lance drilling assembly 60 is then advanced along section 46 so that the drill 90 reaches a blockage. This procedure is similar to that described above for the previous embodiment.

The pressure in sections 42 and 46 and lance 27 for injecting solid particles located upstream of the blockage is then re-increased with an inert purge gas, usually nitrogen gas. The pressure in sections 42 and 46 and the lance 27 for injecting solid particles is equal to the gas pressure inside the direct melting converter with the addition of at least an additional 10 kPa, so that when the drill head 92 breaks through the blockage, the gas pressure upstream of the blockage exceeds the gas pressure in the direct melting converter with the addition of the hydrostatic pressure of the slag 23 at the outlet end 28 of the lance 27, so that the purge gas flows through section 46 and lance 27 to inject solid particles and into the envelope EP direct melting. Thus, the ingress of slag back into the lance for injecting solid particles is prevented after removing the blockage and while removing the drill 90 and extension rods 102 from the lance 27 for injecting solid particles and section 46.

The purge gas is supplied to section 46 and the tuyere 27 for injecting particulate matter by closing the vent valve 58 and supplying purge gas through a discharge line 56 to section 46.

As soon as the plug is removed and purge gas flows through the gas section 46 and the solid particle injection lance 27, the drilling device 77 is removed along the rail 70 to support the drill so that the extension rods can be removed from section 46 and subsequently removed while the drill 90 will not be contained in drill body 76. The latch 88 is placed in the fixing hole 100 in the drill 90 to fix the drill 90 in the housing 76 for the drill. The spherical valve 62 is then closed to isolate the lance drilling assembly 60 from section 46. At this point, the gas pressure in the housing 76 is still an increased purge gas pressure. Accordingly, the tubular section 79 includes an air exhaust valve 81 for controlled discharge of gas under pressure from the housing 76.

The supply of solid material is resumed by opening the valve 52 in section 42. The resumption of this supply makes it possible to stop the supply of purge gas through the discharge line 56.

Although several specific embodiments of the device and method have been described, it should be understood that the device and method can be implemented in many other forms.

In the following claims and in the preceding description, unless the context requires otherwise in relation to the precise wording or necessary implied position, the word “contain” and options such as “comprise” or “comprising” are used in a comprehensive sense, those. to determine the presence of the described features, but not to exclude the presence or addition of additional features in various embodiments of the device and method, as described herein.

Claims (22)

1. A method for removing blockage in a tuyere for injecting solid particles under normal operating conditions of the direct melting converter, which contains a bath of molten metal and slag, the tuyere for injecting solid particles passes into the direct melting converter and has an outlet end immersed in the molten slag, and the only one an inlet connected to a section of the gas supply line and solid remelted material into the tuyere for injecting solid particles, said section of the supply line being located upstream OKU and coaxially with the tuyere for injection of solid particles, including: (a) advancing a tool to remove clogging of solid material through said supply line section and through a tuyere for injecting solid particles to the upstream side of the clogging; (b) removing clogging by said tool under conditions of increased gas pressure so that solid remelted material and gas are supplied through a tuyere for injecting solid particles and into a direct melting converter, while the gas pressure is increased so as to avoid slag entering the outlet end of the tuyere ; and (c) removing said tool from a solid particle injection lance and a feed line section. 2. The method according to p. 1, characterized in that under normal operating conditions of the converter, solid particles transported in the carrier gas under a pressure exceeding the gas pressure in the direct melting converter are supplied to the tuyere for injecting solid particles, and the carrier gas is maintained so so that the section of the feed line and lance, located upstream relative to the clogging, remain at a pressure higher than the gas pressure in the direct melting converter. 3. The method according to p. 1, characterized in that it further includes stopping the supply of carrier gas, and the conditions of the increased pressure of the gas provide a purge gas under pressure in the tuyere for injecting solid particles located upstream relative to the blockage, so that as a result of clogging, the purge gas entered the direct melting converter. 4. The method according to p. 3, characterized in that it further includes resuming the supply of carrier gas after removing the blockage and reducing and then stopping the flow of purge gas after the start of the supply of carrier gas. 5. The method according to p. 1, characterized in that it further includes reducing the pressure in the section of the tuyere for injecting solid particles and sections of the supply line located upstream relative to the blockage, advancing the said tool to the blockage and re-increasing the pressure in the tuyere for injecting solid particles and sections of the supply line before the operation of said tool for removing obstruction. 6. The method according to p. 5, characterized in that the second increase in pressure in the tuyere for injecting solid particles and section of the supply line includes supplying purge gas to the section of the supply line and in the tuyere for injecting solid particles located upstream relative to the blockage. 7. The method according to p. 5, characterized in that the second increase in pressure in the tuyere for injecting solid particles and sections of the supply line includes resuming the supply of carrier gas. 8. The method according to p. 5, characterized in that the pressure in the direct melting converter is under normal operating conditions from 0.5 bar gauge to 1.2 bar gauge. 9. A method according to any one of the preceding paragraphs, characterized in that the tool is a drilling device that removes clogs by drilling a clog. 10. The method according to p. 8, characterized in that the removal of the blockage includes drilling a blockage near the inner side wall of the lance for injecting solid particles to weaken the blockage at the junction with the side wall. 11. The method according to p. 1, characterized in that step (b) comprises connecting said tool to a series of extension rods and advancing the rods into the feed line section and a tuyere for injecting solid particles until the tool reaches an obstruction. 12. The method according to p. 1, characterized in that the solid remelted material includes metalliferous material. 13. The method according to p. 1, characterized in that the solid remelted material comprises a carbon-containing material. 14. Device for removing blockage in the lance for injecting solid particles passing into the direct melting converter, and the lance for injecting solid particles has a single inlet connected to the section of the line for supplying gas and solid particles to the lance for injecting solid particles located upstream and coaxial with the lance for injecting solid particles, while it contains a tool for removing clogging of solid material, which passes through the feed line section and a lance for injecting solid particles stits, and an assembly unit for advancing said tool through a solid particle injection tuyere and a section of the supply line to the blockage on the upstream side of the blockage. 15. The device according to p. 14, characterized in that it further comprises a gas pressure shutter configured to maintain the gas pressure in the lance for injecting solid particles and the supply line section above the gas pressure in the direct melting converter during its normal operation when the tool is moving clogging, removing the clogging and removing it from the feed line section and the tuyeres for injecting solid particles. 16. The device according to p. 14, characterized in that the said tool comprises a drilling head and a drilling device operably connected to the drilling head for its rotation. 17. The device according to p. 15, characterized in that the said assembly unit contains several extension cords for the drill, which are made with the possibility of serial connection to increase the length of the working connection between the drilling device and the drilling head. 18. The device according to p. 16, characterized in that said assembly unit further comprises a drive device for advancing the drill head and extensions for the drill inside the lance for injecting solid particles and removing the drill head and extensions for the drill from the lance for injecting solid particles. 19. The device according to p. 17, characterized in that the drive device is mounted on a rail guide platform, to which is attached a drilling device for reciprocating motion, coaxial with the tuyere for injecting solid particles, and extension cords for the drill contain interconnected links to the reciprocating movement of the platform mounted on the rail led to a corresponding movement of the extensions for the drill and the drilling device.

Images